1. Field of the Invention
The present invention relates to a core retainer for a lock of the type having an interchangeable lock core to securely position an outside knob of the lock in place, thereby allowing rapid and easy change of the interchangeable lock core. The core retainer also may provide an anti-pulling effect to the lock core by means of securely engaging the core retainer with a spindle of the lock.
2. Description of the Related Art
U.S. Pat. No. 5,752,399 to Shen issued on May 19, 1998 discloses a reversible core retainer such that the key used to unlock a door needs not be inverted due to different handing of door. A problem still exists in the lock of the type having an interchangeable lock core removably mounted in an outside knob of the lock. It is found that the knob rotates freely through a small angle in either direction when it is turned, i.e., the knob is not securely retained in place. As a result, replacement of a new interchangeable lock core is difficult as the figure "8" hole of the knob cannot be precisely aligned with the longitudinal hole of the spindle for easy insertion of the lock core. In addition, the core retainer can be easily pulled out along with the lock core in the axial direction, as the engaging strength between the core retainer and the lock core is relatively weak. The present invention is intended to provide an improved core retainer that securely engages with the outside knob to retain the outside knob in place and that provides a reliable anti-pulling effect to the lock core by means of securely engaging the core retainer with the spindle of the lock.